information for our energy future
information for our energy future
The Energy Today website has sought to offset its carbon emissions by purchasing abatement credits for its server and associated energy consumption.
We are aware of recent concerns about the "carbon-neutral myth" 1 and in researching our own website energy consumption it became clear there is currently no standard for these calculations. However, we wanted to do what we could to reduce our impact on the environment.
Since we are not aware of any local hosting companies that use renewable energy and because it is not always easy to move established websites, the approach we took was to purchase renewable energy for the offices of Energy Today and to offset the energy use of the hosting servers by purchasing abatement credits. We sought these credits from reputable providers and have only purchased Australian Government certified abatement credits sourced from genuine abatement activities.
We do not claim to be carbon neutral, but have attempted to offset all possible energy usage related to the website hosting, incorporating generous estimates where the exact details are unknown.
Web pages are provided by web servers, which are computers specially designed to respond to internet requests for web pages.
Servers can host from one to hundreds of websites each, depending on their size and the website requirements. However the server's energy consumption is not going to be very different if it hosts 1 or 50 websites.
To start understanding how to offset our website emissions, we need to know how much energy a web server consumes during the year.
For example, a fully configured Dell PowerEdge 2800 server consumes about 700 W (from Dell's website - this is less than the power supply rating, which is the nominal maximum). If this server runs 24 x 7 the electricity it uses in 1 year comes to 6.13 MWh (8760 hr x 700 / 1,000,000).
However it would not be unrealistic for 1 PowerEdge server to host 50 or more large websites, depending on their size and content (even 800 websites would not be unheard of).
As well as the electricity used by the server, the greenhouse emissions associated with the rest of the hosting process should also be taken into account. This peripheral energy consumption would include the data centre air-conditioning, lighting, other office equipment, and all activities associated with operating the data centre (making coffee, staff travel, printing etc). This can easily be equal to, and indeed more than, the energy consumption of the server. A good overview of data centre energy consumption is given by Jonathan Koomey, Staff Scientist, Lawrence Berkeley National Laboratory and Consulting Professor, Stanford University in his paper Estimating total power consumption by servers in the U.S. and the world 2.
Of course this doesn't take into account the energy that went into the manufacture of the server, (the so-called embodied energy), or also the energy that will be needed to dispose of it. The emissions produced during manufacture will depend on the emission intensity of the energy used, but as a guide, a PC manufactured in California produced about 640 kg CO2 (with a modest emission intensity of 0.4 kg CO2/kWh) or 0.5 kg CO2/$ (Masanet E., L. Price, S. de la Rue du Can, R. Brown, and E. Worrell. 2005. Optimization of Product Life Cycles to Reduce Greenhouse Gas Emissions in California. California Energy Commission, PIER Energy-Related Environmental Research 3. CEC-500-2005-110-F.) Prepared for: California Energy Commission - Public Interest Energy Research Program (pdf) .
In NSW (Australia), most of our electricity is generated by coal-fired power stations, and the emission intensity for electricity in NSW is currently 1.068 tonnes of CO2 per MWh (see AGO workbook 4). So, if it was powered by coal-fired electricity in Australia, this Dell server would be responsible for the emission of 6.55 tonnes of CO2 in 1 year. North American power is largely generated by coal-fired power stations of similar efficiency to those in Australia and also by nuclear and other lower-greenhouse sources. This means that the emission intensity of its electricity supply will be no more than that of the NSW power generation system and could, in fact be somewhat lower.
The Energy Today website is one of about 40 on the server, so we estimate our electricity usage to be about 2.5% of the server total. We double that to take into account the peripheral energy consumption, and double that again for backup systems, storage, switches etc and come up with about 0.65 tonnes of CO2 per year. If we add in the embodied energy and disposal energy amortised over 5 years this all works out to a total energy offset target of slightly less than 1 tonne of CO2 per year. Since we anticipate growth and additional services delivered via the website we have acquitted 2 certificates.
The electricity used at the Energy Today office is also 100% renewable energy, accredited under the National GreenPower Accreditation Program 5.
To our knowledge there are no green hosting services in Australia at present, although we are aware of a few companies who are looking into this.
Some overseas web hosting providers that offer offset or renewable energy powered servers include:
All references are external links. Some publications are only provided by the author in PDF and the relevant agency will need to be contacted for accessible formats. Wherever possible HTML or RTF formats have been sourced.
